The present invention relates to a set of light-weight wheels having a hollow axle and journal means.
Twin wheels, or two-wheel sets, are mostly constructed in that two individual wheels are forced onto a solid axle. The resulting assembly is heavy, requires extensive additional work, and complicated steps are to be taken for tests. Also, the press fit zone experiences maximum load and wear.
German Pat. Nos. 876 697 and 963 158 disclose such wheels in which the axle is of a hollow construction. However, these types of wheels do not withstand present-day load requirements. Early material fatigue can be observed in certain cross sections of the axle particularly adjacent to the press fit area. Cracks and fractures result from this high sensitivity to notching. These facts have been recognized and lead to constructions as shown in German Pat. Nos. 864 885 and 864 408, according to which press fit was replaced by welding the hollow shaft to the wheel. However, repetition of bending stress leads to early damage of the weld joint.
Following the general teaching of the early German Pat. Nos. 544 626, it has been proposed to shrink fit wheels onto a tubular carrier, and a forced internal sizing bushing is used to stabilize the press fit on the hollow shaft. It has been tried to reduce stress peaks in this construction by means of adhesive bonding, under elimination of the press fit. However, this approach requires too many parts and light working tolerances.